FIELD OF THE INVENTION
[0001] The invention relates generally to industrial roll-up doors, and more particularly
to an improved, breakaway side guide extension mechanism for a roll-up door.
BACKGROUND OF THE INVENTION
[0002] Roll-up doors are used in a variety of industrial applications, typically for the
purpose of separating areas within a building, or closing off building entries from
the outside. A typical roll-up door comprises a fabric curtain which is wound about
a roller journalled for rotation above the doorway with which the roll-up door is
associated. To close the door, the roller is rotated such that the curtain pays off
of the roller to enclose the doorway. Of course, the door is opened by reversing the
direction of the roller and rolling the fabric curtain onto the roller. Such roller
doors are typically either powered opened and closed, or are powered open and allowed
to fall closed by gravity.
[0003] When the roll-up door is placed over an exterior doorway of a building, provision
must be made to prevent the fabric curtain from billowing due to wind being applied
from the outside. Similarly, when the roll-up door is in place between different sections
of a warehouse, there may be pressure differentials between these two sections, which
may also cause billowing of the roll-up door if the door does not have provision to
prevent this from happening. Such billowing is problematic because it affects door
function and may allow leakage past the door. To correct for this problem, roll-up
doors typically include bottom member in the form of a rigid or semi-rigid bottom
bar to provide so-called "wind retention" or prevention of undesirable billowing.
The bottom bar typically extends across the leading width of the door, and also includes
extensions which extend past either side of the door. These extensions are typically
received within side frames disposed on either side of the door and run vertically
along the side of the doorway. As the door moves between its open and closed positions,
the bottom bar and its extensions or "side frame inserts" move within a generally
vertical plane since they are guided within the generally vertical side frames which
may include a guide track for that purpose. With the leading edge of the door thus
restrained within a vertical plane, movement of the fabric curtain of the door out
of that vertical plane is largely avoided. However, the bottom bar only ensures that
the leading edge of the door stays in the vertical plane, and strong gusts of wind
or large pressure differentials between sections of a building may still allow the
remainder of the curtain to billow either during the curtain's travel, or when it
is fully closed.
[0004] To prevent this undesirable movement of the door, many prior art doors use a tensioning
means to place a vertically disposed tension on the door to prevent it from billowing
out of the vertical plane. One example of such a tensioning means is a heavy bottom
bar. The weight of the heavy bottom bar may provide sufficient vertical tension to
prevent undesirable billowing particularly in a gravity-fall type door. Alternatively,
external means may be used to provide the necessary tension. For example, belting
is often used for this purpose. Typically, one end of the belting is attached to a
roller pulley, and is wound and unwound from the roller in the opposite sense from
the curtain. The belt is then passed through a pulley mounted near the bottom of the
side frame. The other end of the belt is then attached to the side from insert of
the bottom bar. As the belt is wound and unwound from the roller in an opposite sense
to the curtain, it exerts a downward pulling force on the bottom bar and the side
frame inserts thus placing the necessary vertical tension on the door. This pulling
force may be enhanced by a torsion spring disposed in the roller and engaging the
roller pulley as in U.S. Patent 4,887,660 which is assigned to the Assignee of the
present invention. Forces may also be applied directly to the belt as in U.S. Patent
4,997,022. Other particular arrangements for the belting besides those previously
described are also used to achieve the same purpose.
[0005] A further exemplary means for exerting the necessary vertical tension on the door,
at least in the closed position, is a system wherein the side frame inserts of the
bottom bar are latched in position when the door is in the closed position. In the
case of the powered roll-up door, the motor is then reversed to exert the necessary
vertical tension of the door to hold it taut.
[0006] While the variety of methods just described for providing wind retention are generally
effective for that purpose they are not without their own disadvantages. For example,
obstacles in the path of travel of the bottom bar may be problematic. If an obstacle
is in place in this position, and the door continues its downward movement, damage
to either the door or the object could occur. Further, if the obstacle should be warehouse
or other personnel, either damage to the door or injury to the personnel could result.
To avoid this problem, doors employing bottom bars typically also include some type
of sensing mechanism for determining when an obstacle has been encountered. These
sensors are coupled to the motor which drives the roller, and cause the door to be
reversed upon encountering an obstacle.
[0007] Since this type of door is often used in a warehouse environment, where forklifts
are employed, roll-up doors are also subject to being struck by such forklifts, thus
putting an unwanted horizontal or other impact force on the door. Of course, other
sources of such forces besides forklifts may also be encountered. Typically, such
impacts on the door occur while the door is in the middle of its range of travel.
A simple rigid bottom bar with side frame members extending beyond the edge of the
door and into side frames, will be subject to damage upon impact. That is, it could
either be bent or broken, in either event probably requiring replacement.
Alternatively, if the bottom bar is rigid enough, damage to the object striking it
may occur. To avoid this problem, many bottom bars include a breakaway mechanism,
that allow the bottom bar attached to the bottom of the door to be separated from
the side frame inserts upon application of a horizontal force above a certain magnitude.
Since the side frame inserts typically become separated from the bottom bar in these
breakaway mechanisms, they must be reassembled after a breakaway condition occurs.
In the case where the side frame inserts are attached to belts the other end of which
is attached to the roller, such reattachment can be problematic since the elasticity
of the belts must be overcome to re-place the side frame inserts adjacent to the bottom
bar. Further, regardless of whether the side frame inserts are attached to belting,
the breakaway condition may be dangerous since the side frame inserts can fall by
gravity and potentially injure personnel below.
[0008] An example of such a breakaway mechanism is found in US-A-5 271 448 which discloses
a breakaway guide assembly and a method of releasable coupling an end of a roll-up
door bottom member to a guide extension according to the preamble of claims 1 and
15, respectively. More specifically, US-A-5 271 448 describes and shows a conventional
roll-up door including a breakaway guide follower having a first part attached to
a raising and lowering mechanism and a second part attached to the curtain. The first
part defines a pivotable latch plate having a slot therein, and the second part of
the guide follower defines a pin received in the slot. In response to forces applied
into the plane of the door curtain above a certain magnitude the latch plate rotates
to a release position in which the second retaining element is allowed to move away
transversally to allow the door curtain to break away. However, such a breakaway mechanism
does not provide vertical breakaway when, for example, the descending door curtain
abuts to an obstruction placed in the doorway.
[0009] US-A-5 025 847 discloses a similar breakaway guide assembly wherein the breakaway
mechanism consists of a sliding engagement of the first and second parts thereof.
[0010] Furthermore, US-A-5 056 579 discloses a roll-up door having a flexible door curtain
which comprises a reinforcing bottom bar for stiffening and guiding the flexible curtain
along vertical guide members. At each of its ends, the reinforcing bar comprises flexible
end pieces to enable the bar to escape from the guide members when it is subjected
to a force perpendicularly to the curtain. The bar is constituted, for example, by
a tube having two protective end pieces fitted to its respective ends, with the end
pieces being designed to break or to escape from the tube in response to a horizontal
force.
[0011] Thus while the presence of such breakaway mechanisms can avoid the need to replace
the bottom bar upon each impact, employment of such a breakaway mechanism is not without
its own disadvantages. Further, such breakaway mechanisms typically allow for breakaway
only upon application of a horizontal force perpendicular to the plane of the door.
Provision is typically not made for breakaway due to either a vertical force or forces
having both horizontal and vertical components, and such doors still require a sensor
or other means, described above, for preventing impact with obstacles in the doorway.
SUMMARY OF THE INVENTION
[0012] It is thus a general aim of the invention to improve on breakaway side frame inserts
as compared to those that have been used heretofore.
[0013] In accordance with that aim, it is an object of the invention to provide a breakaway
guide assembly, which breaks away not only for horizontally applied forces but also
those applied vertically and in other directions.
[0014] It is a further object of the invention to provide a breakaway guide assembly that
can be adjusted to provide a breakaway function for different environments of use.
[0015] It is a further object of the invention to provide a breakaway guide assembly that
is simple to implement, and does not require a replacement of parts upon breakaway.
[0016] It is also an object of the invention to provide a breakaway guide assembly that
has enhanced safety features.
[0017] It is a related object to provide a breakaway guide assembly where free fall of detached
components of the assembly is prevented.
[0018] Other objects and advantages of the invention will become apparent from the description
to follow.
[0019] In accordance with these and other objects, there is provided a breakaway guide assembly
according to independent claim 1 and a method of releasable connecting an end of a
roll-up door bottom member on the leading edge of a door curtain to a guide extension
according to independent claim 15. The dependent claims refer to preferred embodiments
of the present invention.
[0020] The bottom member may be rigid, semi-rigid or flexible. The omni-directional breakaway
guide assembly is comprised primarily of a guide extension for engaging vertical guide
members to guide the door in a vertical plane, and a bottom member portion coupled
to the bottom member. The breakaway guide assembly includes a magnetic coupling between
the guide extension and the bottom member portion, illustratively in the form of a
coupling magnet fixed to the guide extension, and a magnetic cup assembly forming
part of the bottom member portion. The magnetic cup assembly includes a ferrous member
at least against the wall closest to the bottom member. The remainder of the magnetic
cup assembly may be non-ferrous, and may illustratively partially surround the coupling
magnet fixed to the guide extension. The magnetic attraction between the coupling
magnet and the ferrous member in the magnetic cup assembly releasably attaches the
guide extension to the bottom member portion, and thus to the bottom member. Upon
application of a sufficient force on the bottom member, however, this magnetic attachment
is overcome and the bottom member and attached bottom member portion break away from
the guide extension. Due to the nature of the magnetic coupling between the coupling
magnet and the ferrous member in the magnetic cup assembly, such breakaway may occur
for forces applied in a variety of directions to the bottom member.
[0021] According to a preferred embodiment of the invention, the guide assembly is a side
frame insert in the form of a trolley including roller wheels which engage in a vertically
disposed guide track in the vertically extending guide member, or side frame. A first
c-shaped bracket is attached to the side frame insert outside of the side frame. A
second, oppositely-facing c-shaped bracket is received within the first c-shaped bracket,
and is fixedly coupled to the coupling magnet. A hinge pin is connected between the
first and second c-shaped brackets, to allow the coupling magnet to pivot relative
to the trolley. As a result, upon application of a horizontal breakaway force on the
bottom member, some pivoting of the coupling magnet relative to the side frame insert
will occur prior to the breakaway condition.
[0022] According to a further preferred embodiment of the invention, a hinge spring is disposed
around the hinge pin, and serves to apply a rotational force to the coupling magnet,
especially following breakaway. This rotational spring force is overcome when the
coupling magnet is attached to the bottom member through the magnetic cup assembly.
Upon breakaway, however, the rotational force is exerted on the coupling magnet causing
it to swing toward and engage one of the side frames. If the side frame is made of
a ferrous material, this magnetic engagement between the coupling magnet and the side
frame will hold the side frame insert in place vertically. In the event a non-ferrous
side frame is used, the coupling magnet may be advantageously provided with a high
friction strip in the area of the coupling magnet where it engages the side frame.
This, similarly, will cause the side frame insert to be retained in its vertical position
upon breakaway. Such a feature is highly advantageous from a safety perspective, since
the broken-away side frame insert will not be allowed to freely fall after breakaway.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023]
Figure 1 is an elevational view of the leading edge of a roll-up door including an
omni-directional breakaway guide assembly according to one embodiment of the invention,
shown in combination with an adjustable soft bottom member;
Fig. 2 is a side sectional view of the magnetic cup assembly according to an embodiment
of the invention;
Fig. 3 is a rear elevational view of a magnetic cup assembly according to an embodiment
of the invention;
Fig. 4 is a top view of the guide extension according to an embodiment of the invention;
Fig. 5 is a side sectional view of the guide extension of Fig. 4; and
Fig. 6 is a top view showing a portion of the hinge and coupling magnet according
to one embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] While the invention will be described in connection with certain preferred embodiments,
there is no intent to limit it to those embodiments. On the contrary, the intent is
to cover all alternatives, modifications and equivalents included within the scope
of the invention as defined by the appended claims.
[0025] Turning now to the figures, FIG. 1 shows an elevational view of an omni-directional
breakaway guide assembly according to one embodiment of the invention. As the breakaway
guide assembly according to the invention would have the same implementation on either
side of the door, reference will only be made to the assembly shown on the left hand
side of FIG. 1, for ease of reference. The breakaway guide assembly according to the
invention is designated generally by reference numeral 10. Breakaway guide assembly
10 is disposed between the leading edge 20a of a conventional roll-up door curtain
20 and a vertically extending guide member in the form of a side frame 30. As is true
in many conventional roller door installations, the side frame 30, along with a matching
side frame on the other side of the door, supports the roller upon which the door
curtain is wound and unwound. In this embodiment, side frame 30 is formed with a vertically
extending track in the form of a gap 36, seen in FIG. 4. The gap 36 receives a generally
planar member or plate 125 forming a part of the breakaway guide assembly. The plate
engages the gap 36 to guide the door in a vertical plane during travel. While the
present embodiment is thus limited to a so-called "side frame insert" received within
a channel in the side frame, the scope of the invention is not so limited. Rather,
the invention covers other forms of vertically extending guide members and guide extensions
guidingly engaging those guide members, as discussed in greater detail below. According
to a preferred embodiment of the invention, the breakaway side frame insert 10 is
also used in combination with a side frame 30 having a vertically extending, horizontally
disposed projection shown in broken lines in FIG. 1 at 35, to also be discussed in
greater detail below.
[0026] Breakaway side frame insert assembly 10 is divided generally into a guide extension
40 and a bottom member portion 45. According to this embodiment, the guide extension
40 is received within the side frame 30, in a vertically extending channel which prevents
movement of the guide extension 40 into and out of the plane of the doorway, defined
by the plane of the page in FIG. 1. As mentioned, however, other specific structures
of vertically extending guide member (side frame) and guide extension could be used
to provide the same guiding engagement between these 2 members. The bottom member
portion 45 of breakaway guide assembly 10 is coupled to a bottom member 50 disposed
along the leading edge 20a of the door curtain 20. The bottom member 50 may be rigid
(such as a conventional bottom bar), semi-rigid, or flexible.
[0027] An exemplary bottom member, and the bottom member which is used with the breakaway
guide assembly according to the invention in its preferred embodiment, can be found
in an applicant's U.S. Patent Application filed concurrently herewith. While the concurrently-filed
application includes significant detail regarding the structure and function of the
adjustable soft bottom member, a brief review of its structure and function are included
herein for ease of understanding of the present invention. In one embodiment, the
adjustable soft bottom member 50 is comprised primarily of a resilient strap 60 stretching
along the leading edge 20a of the roller door curtain 20. At either end of the door,
strap 60 is received within semi-rigid end stiffeners 65, 66. Resilient strap 60 is
then stretched when the guide extension 40, and bottom member portion 45 of the breakaway
guide assembly on either side of the door and according to the invention, are coupled
together. The resilient strap thus provides rigidity across the leading edge 20 of
the curtain, but is also substantially conformable and deflectable upon impact of
the leading edge with an obstruction during travel of the door. The bottom member
portion 45 of the breakaway guide assembly 10 according to the invention is connected
to the bottom member 50, for example, as by the bolts 70 shown in FIG. 1. With the
bottom member portion 45 attached either to exemplary bottom member 50, or other,
conventional bottom members, and with guide extension 40 guidingly engaging the side
frame 30, the two halves 40, 45 are coupled together for the purpose of providing
the breakaway feature.
[0028] According to one aspect of the invention, this coupling between guide extension 40
and bottom member portion 45 is achieved by means of a magnetic coupling. The magnetic
coupling in such an environment is advantageous for several reasons. With two contacting
surfaces held together by means of a magnetic field, that coupling is omni-directional.
That is, the magnetic field coupling will resist any force exerted on either side
of the coupling which tends to move the two mating surfaces relative to each other.
Thus, either a force tending to separate the two surfaces or a shear force tending
to slide the two surfaces relative to each other will be resisted. Such an omni-directional
coupling is useful in this environment since a variety of damaging forces may be exerted
on the door. With the use of an omni-directional coupling according to the invention,
undesirable results from these damaging forces can be avoided by providing for breakaway
of the bottom member from the guide extension. Magnetic coupling is also advantageous
as it is easily adjustable to differing environments. As will be discussed in greater
detail below, the preferred embodiment for the magnetic coupling according to the
invention is a coupling magnet and a ferrous member. A ferrous member is used herein
to refer to a member comprised of material exhibiting ferromagnetic and/or electromagnetic
properties. The coupling strength between these two elements can be modified by either
changing the magnetic strength of the coupling magnet, changing the ferrous content
of the ferrous member, or making the ferrous member a magnet itself. By simply substituting
components having different magnetic properties, the magnitude of the breakaway forces
which will be sustained prior to the inventive breakaway side frame assembly breaking
away, can be easily adjusted. Moreover, adjustment of the magnetic coupling can be
achieved by making either or both of the coupling magnet and the ferrous member an
electromagnet, and adjusting the applied current.
[0029] According to the present embodiment, this magnetic coupling is achieved by means
of a coupling magnet 80 fixed to the guide extension 40, and a magnetic cup assembly
85 which forms a part of the bottom member portion 45. Coupling magnet 80 and magnetic
cup assembly 85 are shown in their coupled position in FIG. 1. Magnetic cup assembly
85 is comprised of two elements, a plastic cup 90 shown in a side sectional view in
FIG. 2 and a rear elevational view in FIG. 3, and an illustratively T-shaped ferrous
member 95, also shown in the sectional view of FIG. 2. Cup 90 includes a slot 100
in its rear face 105. By "rear" face, it is meant that face of the cup 90 which is
closest to the bottom bar 50 (see FIG. 1). Slot 100 is dimensioned to receive a tab
97 forming a part of T-shaped ferrous member 95. The other part comprising T-shaped
ferrous member 95 is a ferrous plate 98. As can be seen from FIG. 3, the ferrous plate
is adapted to abut the rear wall of cup 90, and tab 97 extends past the rear of the
cup, toward the bottom member 50. Tab 97 preferably includes mounting holes 99 for
fixing T-shaped ferrous member 95 to the bottom member. According to the preferred
embodiment, the ferrous plate 98 is adhesively fixed to the rear wall 105 of the cup
90. It will be appreciated that this embodiment of the bottom member portion 45 is
exemplary and not restrictive. Other embodiments are possible, and would require only
a ferrous member and some means for coupling the ferrous member to the bottom member.
Moreover, it should be noted that, although the present embodiment includes a coupling
magnet on the guide extension and a ferrous member on the bottom member portion, the
invention is not so limited. Rather, the invention covers a magnetic coupling between
the guide extension and bottom member portion, regardless of the location of the magnets
and/or ferrous members.
[0030] Returning to the preferred embodiment, to attach the guide extension 40 to the bottom
member portion 45, coupling magnet 80 is preferably received within the cup 90 of
the magnetic cup assembly 85, as seen in FIG. 1. The side walls of the cup 90 assist
in aligning coupling magnet 80 with the ferrous plate 98 of the ferrous member 95.
According to the present embodiment, the walls of cup 90 also serve to prevent movement
of coupling magnet 80 relative to the ferrous plate 98 in the plane of the contact
surface between those two members. Such a constraint on the range of motion of the
coupling magnet 80 relative to the ferrous plate 98 could limit the breakaway capabilities
of a breakaway guide extension assembly designed in this manner. According to the
present embodiment, however, such a design was preferred, since other means, to be
described below, were used to overcome this potential drawback, and give the assembly
enhanced breakaway performance.
[0031] Returning to FIG. 1, it can be seen that the coupling magnet 80 forms a part of the
guide extension 40 to now be described in greater detail. According to this embodiment,
the portion of the guide extension 40 received within side frame 30 is in the form
of a trolley assembly 120 shown in top view in FIG. 4. Trolley assembly 120 includes
a trolley plate 125 and at least two trolley wheels 130. According to the preferred
embodiment, four trolley wheels are provided as seen in reference to FIGS. 4 and 5.
A pair of trolley wheels 130 are each mounted on spindles 135. The top view of FIG.
4 also shows a sectional view of the side frame 30. The side frame is of a conventional
design, including two vertically disposed members 31 including horizontal projections
or inner faces 35. A gap 36 is formed between the two vertically disposed members,
and is sized to receive the trolley plate 125. Trolley wheels 130 are placed on trolley
plate 125 such that they engage the projections 35 to prevent trolley assembly 120
from being pulled in a horizontal direction out of the side frame as indicated by
the arrow 140 in FIG. 4. Thus, according to this embodiment trolley assembly 120 is
horizontally restrained by the engagement of trolley wheels 130 with the horizontal
projection 35. While the trolley assembly just described is a preferred embodiment
of the invention, it is only a representative example. If the breakaway side frame
insert mechanism is used with an adjustable soft bottom member as in concurrently
filed application, a horizontally restricted insert member like trolley 120 is used.
However, for the general case of a rigid bottom bar, the guide extension 40 may or
may not be horizontally restrained, and only needs a surface for guidingly engaging
the side frame for guided vertical movement.
[0032] Turning to the side view of the guide extension 40 of FIG. 5, the preferred coupling
between trolley assembly 120 and coupling magnet 80 is shown. That preferred coupling
is in the form of a hinge 150 formed by a first c-shaped member 155 and second c-shaped
member 160, coupled together by a hinge pin 170. FIG. 6 shows the second c-shaped
member 160 as attached to the coupling magnet 80. As can be seen from that figure,
the top end of the second c-shaped member is roughly semicircular in shape and includes
a central hole 161 for receiving hinge pin 170. It also includes a rear plate 162
which is coupled to the coupling magnet assembly 80. In the present embodiment, coupling
magnet 80 is in the form of two steel plates 81 and 82. A stainless steel cup 83 is
welded between plates 81 and 82, with an opening facing towards the bottom bar. Magnets
are disposed within the cup 83 and a plate 84 is welded across the opening. Of course,
several other potential embodiments of coupling magnet assembly 80 are possible.
[0033] Returning to FIG. 5, it will be seen that a hinge spring 175 is disposed over hinge
pin 170, and engages first and second c-shaped members 155, 160 (see FIG. 5). The
function of hinge spring 175 will be discussed in greater detail below. Further, having
described the structural details of the breakaway guide assembly according to this
embodiment of the invention, its function will now be described in greater detail.
[0034] For the purposes of this description, two types of potentially damaging external
forces which may be applied to a roll-up door will be described. The first is a force
caused by an exterior object striking the door. In the typical case of use of the
roll-up door in a warehouse environment, that external object will most likely be
a forklift. Typically, roll-up doors in that environment include some type of sensor
or treadle in the floor in front of the door which causes the door to open when activated
by passage of a forklift. If the forklift is traveling in excess of the speed under
which it must be traveling to allow the door to move out of the way before arrival
of the forklift, or if the sensor or treadle is malfunctioning, the forklift may make
contact with the roll-up door. Accordingly, the typical contact between the forklift
and the door would be while the door is in the midst of its range of travel, typically
upward. If the sensor or treadle is malfunctioning completely, contact between the
forklift and the door may occur while the door is in the closed position. Of course,
contact between the door and the forklift is not expected in the fully raised position
of the door. Furthermore, other external objects besides forklifts may contact the
door.
[0035] In the case of the external force such as that exerted by a forklift, which is in
a generally horizontal direction the breakaway guide assembly according to the invention
will breakaway if that external force is above a predetermined magnitude. The breakaway
sequence in regard to the application of a horizontal force is the same regardless
of whether a rigid, conventional bottom bar is used or whether an adjustable soft
bottom bar as disclosed in the applicant's U.S. Patent Application, filed concurrently
herewith, is used. In either case, the bottom member initially begins moving in a
horizontal direction upon application of the external force. As mentioned above, however,
the vertical side walls of the cup 90 comprising a part of magnetic cup assembly 85
initially prevent the coupling magnet 80 from moving in the same direction. Instead,
because of the presence of the hinge 150 in place between the trolley assembly 120
and coupling magnet 80, the coupling magnet initially pivots about the hinge pin 170
and traces out an arc such that the mating faces of the coupling magnet 80 and the
ferrous plate 98 maintain engagement during this first portion of the horizontal motion
of the bottom member. As that bottom member motion continues, however, that rotational
motion will reach its outer limit and a component of the horizontal force perpendicular
to the mating faces of the coupling magnet 80 and the ferrous plate 98 will overcome
the magnetic coupling between those two members, thus causing the bottom member portion
45 and the guide extension 40 of the breakaway guide assembly 10 to separate, and
thus "breakaway".
[0036] The breakaway sequence for a horizontal force just described is advantageous in the
environment in which the door will be used. The side walls of the magnetic cup assembly
85 and the presence of the hinge assembly 150 according to this preferred embodiment
allow the door to move horizontally a limited amount before any pulling force tending
to separate coupling magnet 80 and ferrous plate 98 is encountered. As a result, for
a horizontal force applied over a small distance, the bottom member would be allowed
to move a limited amount without the door breaking away. This could be the case even
if a very small magnetic force held coupling magnet 80 and ferrous plate 98 together
since a force tending to separate magnet 80 and plate 98 may not even be exerted on
these two members if the range of travel of the door caused by the horizontal force
is small enough. It should also be noted that this advantageous function is illustratively
provided by the hinge assembly 150 allowing pivotal movement, and by the magnetic
cup assembly 85 initially engaging the sides of the coupling magnet 80. One skilled
in the art will appreciate that this function could be achieved by alternative structure.
For example, the pivotal movement need not be provided by a hinge, but could be provided
by a resilient member connecting the coupling magnet and the trolley. Moreover, the
pivotal movement may be provided on the bottom member portion as opposed to the guide
extension. Finally, a strictly "pivotal" movement is not required, and a bending or
other relative displacement could achieve the same function. It should also be noted
that this breakaway guide mechanism will break away from impacts on either side of
the door. The gap 36 engaging both sides of the trolley plate 125 restrains the guide
extension 40 in both of the horizontal directions perpendicular to the door. Of course,
other guiding engagements between the guide extension and vertically extending guide
members could provide such breakaway, or breakaway only in one of these directions.
[0037] The breakaway guide assembly according to the invention also advantageously provides
a breakaway function for forces applied in the plane of the door. An example of such
a force would be that exerted on the door by contact between a descending door and
an obstruction placed in the doorway. In the preferred embodiment, wherein the breakaway
guide assembly is coupled to an adjustable soft bottom member as disclosed in the
concurrently filed U.S. Patent Application, breakaway for this condition would occur.
If the breakaway guide assembly were modified within the scope of the present invention,
breakaway for a rigid bottom bar for the same condition would also be possible.
[0038] For the first case of the use of breakaway guide assembly 10 with an adjustable soft
bottom member as in the concurrently-filed application, it will be appreciated that
the soft bottom member will illustratively deform upwardly in the area of the obstruction
that it encounters during its downward travel. As a result, the portions of the door
on either side of the contact between the door and the obstruction will assume an
upward angle toward the point of contact. Continued travel of the door downward will
cause a pulling/separating force to be exerted on the ferrous member 98 relative to
the coupling magnet 80, since the coupling magnet 80 will maintain its horizontal
orientation. The top and bottom walls of the magnetic cup assembly 85 may initially
maintain the coupling magnet face and the face of the ferrous member 98 in engagement,
but the separating force will eventually overcome the magnetic attraction between
these two members, thus resulting in breakaway. Use of the magnetic breakaway side
frame insert assembly according to the invention will also provide breakaway for a
force applied in the plane of the door if a conventional, rigid bottom bar is used.
In that case, the magnetic cup assembly 85 could illustratively be modified to either
remove or reduce the length of the top and bottom walls of the cup. Accordingly, upon
application of the force in the plane of the door, the faces of the coupling magnet
80 and ferrous member 98, assuming that the force overcomes their magnetic attraction,
could slide relative to each other in a generally vertical plane, until breakaway
occurs.
[0039] To add enhanced safety to the operation of the door, and to prevent injury or other
accidents from occurring upon breakaway, the hinge assembly 150 may have an additional
advantageous function. In present doors, a breakaway condition is potentially hazardous
because the broken-away side frame inserts may fall to the ground. This occurs by
virtue of gravity, and, in the case of side frame inserts coupled to the roller by
means of tensioning straps, the gravitational force is potentially enhanced by an
elastic restoring force from the tensioning straps pulling on the side frame inserts.
This hazard is prevented according to the present invention by means of the guide
extension 40 of the breakaway guide assembly 10 including a mechanism for locking
the insert half to the side frame upon breakaway. In the present embodiment, the hinge
assembly 150 allows this function. Upon breakaway occurring, coupling magnet 80 and
the attached second c-shaped member 160 are rotated under the action of the hinge
spring 175 (see FIG. 4). The rotation is in the sense of the arrow 190. Hinge spring
175 causes rotation of the coupling magnet 80 until the magnet engages the side frame
30. Assuming the side frame is made of a ferrous material, this contact between coupling
magnet 80 and side frame 30 will hold the guide extension 40 in place vertically along
the side frame, thus preventing it from falling from the floor and potentially injuring
warehouse personnel. In the alternative, the side frame 30 may be made of a non-ferrous
material such as aluminum. In that event, a high-friction material may be fixed to
the side walls of the coupling magnet 80. This strip of high-friction material is
labeled 200 in FIG. 1. Again, as hinge spring 175 rotates coupling magnet 80 about
hinge pin 170, the coupling magnet 80 and high-friction strip 200 will engage the
side frame. The friction between strip 200 and side frame 30 will be sufficient to
maintain guide extension 40 in its vertical position along the side frame, again preventing
potential injury to personnel in the vicinity. One skilled in the art will appreciate
that other means beside a spring-loaded hinge could be used to rotate the coupling
magnet relative to the trolley plate.
[0040] Of course, the above descriptions have assumed application of idealized horizontal
forces and forces in the plane of the door. In reality, forces exerted on the door
will be a combination of such forces. The magnetic coupling of the invention, however,
is omni-directional as discussed above, and can be used to provide breakaway operation
for wide range of applied forces. Further, the ease of manufacture and assembly, and
the ability to adjust the coupling strength between the magnet 80 and the ferrous
member 98 are significant advantages of the invention.
1. A breakaway guide assembly for use on a roll-up door, the roll-up door including a
bottom member (50) on the leading edge (20a) of a door curtain (20), vertical guide
members (30) being disposed on either side of the door for receiving and guiding the
guide assembly in a vertical plane, the breakaway guide assembly comprising:
a guide extension (40) being engageable with the vertical guide members (30) to guide
the door curtain (20) in a vertical plane;
a bottom member portion (45) being coupable to an end of the bottom member (50) and
extending toward the guide extension;
characterised by:
a magnetic coupling (80,85) between the guide extension (40) and the bottom member
portion (45), the magnetic coupling releasably mating the guide extension (40) and
bottom member portion (45) for forces applied to the door curtain (20) below a predetermined
magnitude.
2. The breakaway guide assembly of claim 1, wherein the magnetic coupling comprises a
coupling magnet (80) attached to the guide extension (40) and a ferrous member (95)
attached to the bottom member portion (45).
3. The breakaway guide assembly of claim 2, wherein the guide extension (40) includes
a planar insert member (120) received within the vertical guide member (30).
4. The breakaway guide assembly of claim 3, wherein the planar insert member is a trolley
plate (125), the trolley plate receiving trolley wheels (130), the vertical guide
member (30) including a vertically extending horizontal projection (35) for engaging
the trolley wheels and restricting horizontal movement of the guide extension (40)
towards the door curtain (20).
5. The breakaway guide assembly of claim 1, wherein a pivotal movement is provided on
the bottom member portion (45) or on the guide extension (40).
6. The breakaway guide assembly of claim 3, wherein the planar insert member and the
coupling magnet are pivotally attached.
7. The breakaway guide assembly of claim 6, wherein the pivotal attachment comprises
first and second c-shaped members (150,160), the first c-shaped member being attached
to the planar insert member, and the second c-shaped member being attached to the
coupling magnet, the first and second c-shaped members facing each other, and being
pivotally connected by a pin (170).
8. The breakaway guide assembly of claim 7, wherein a spring (175) engages the first
and second c-shaped members for applying a rotational force to the second member relative
to the first, whereby separation of the magnetic coupling allows the coupling magnet
to swing about the pin to contact a side frame and maintain the insert half in the
same vertical position.
9. The breakaway guide assembly of claim 8, wherein the coupling magnet includes a high-friction
strip (200) on a portion which contacts the side frame after separation of the magnetic
coupling, the friction between the strip and the side frame maintaining the insert
half in the vertical position.
10. The breakaway guide assembly of claim 2, wherein the ferrous member is a magnet.
11. The breakaway guide assembly of claim 2, wherein the coupling magnet is an electromagnet.
12. The breakaway guide assembly of claim 1, wherein the bottom member portion (45) is
coupled to an adjustable soft bottom member (50).
13. The breakaway guide assembly of claim 2, wherein the coupling magnet (80) being pivotally
attached to the guide extension (40) such that, following separation of the coupling
magnet from the bottom member portion (45), the coupling magnet can rotate relative
to the guide extension (40) and engage the vertical guide member (30) to retain the
guide extension (40) in a vertical position.
14. The breakaway guide assembly of claim 13, wherein the guide extension (40) and coupling
magnet (80) are hinged attached and a spring (175) is coupled to the hinged attachment
to rotate the coupling magnet (80) relative to the guide member upon breakaway.
15. A method of releasably connecting an end of a roll-up door bottom member (50) on the
leading edge (20a) of a door curtain (20) to a guide extension (40) received within
and guided in a vertical plane by a vertically extending guide member (30) disposed
on one side of the door, the method comprising the steps of:
providing the guide extension (40) which guidingly engages the vertically extending
guide member (30) to guide the door curtain (20) in a vertical plane;
characterised by:
magnetically coupling the guide extension (40) to a bottom member portion (45) coupled
to the bottom member (50); and
allowing the magnetic coupling to be broken upon application of a force to the door
curtain (20) above a predetermined magnitude.
16. The method of claim 15, including providing the guide extension (40) with a second
coupling member pivotally attached to the guide extension (40), and locking a side
frame insert to a side frame after the coupling is broken, to prevent the side frame
insert from falling.
17. The method of claim 16, wherein the step of locking the side frame insert comprises
rotating the second coupling member about the pivotal attachment of the guide extension
(40) to cause the second coupling member to engage the vertically extending guide
member (30).
18. The method of claim 17, including the step of magnetizing the second coupling member
to magnetically couple the coupling member to the vertically extending guide member
(30).
19. The method of claim 17, including the step of providing the second coupling member
with a friction strip to frictionally couple the second coupling member to the vertically
extending guide member (30).
1. Trennbare Führungsvorrichtung zur Verwendung an einem Rolltor, wobei das Rolltor ein
Bodenelement (50) an der Vorderkante (20a) eines Torvorhanges (20), vertikale Führungselemente
(30), welche an beiden Seiten des Tores zum Aufnehmen und Führen der Führungsvorrichtung
in vertikaler Ebene angeordnet sind, aufweist, wobei die trennbare Führungsvorrichtung
aufweist:
einen Führungsansatz (40), der mit den vertikalen Führungselementen (30) in Eingriff
bringbar ist, um den Torvorhang (20) in vertikaler Ebene zu führen;
einen Bodenelementabschnitt (45), der mit einem Ende des Bodenelements (50) verbindbar
ist und sich zum Führungsansatz hin erstreckt;
gekennzeichnet durch:
eine magnetische Kopplung (80, 85) zwischen dem Führungsansatz (40) und dem Bodenelementabschnitt
(45), wobei die magnetische Kopplung den Führungsansatz (40) und den Bodenelementabschnitt
(45) für am Torvorhang (20) anliegende Kräfte unterhalb einer vorgegebenen Größe lösbar
zusammenhält.
2. Trennbare Führungsvorrichtung nach Anspruch 1, bei welcher die magnetische Kopplung
einen Kopplungsmagneten (80), der an dem Führungsansatz (40) befestigt ist, und ein
eisenhaltiges Glied (95) aufweist, das an dem Bodenelementabschnitt (45) befestigt
ist.
3. Trennbare Führungsvorrichtung nach Anspruch 2, bei welcher der Führungsansatz (40)
ein ebenes Einsatzteil (120) umfaßt, welches in dem vertikalen Führungselement (30)
aufgenommen ist.
4. Trennbare Führungsvorrichtung nach Anspruch 3, bei welcher das ebene Einsatzteil eine
Förderplatte (125) ist, wobei die Förderplatte Förderräder (130) enthält, bei welcher
das vertikale Führungselement (30) einen vertikal verlaufenden Seitenvorsprung (35)
aufweist, um mit den Förderrädern in Eingriff zu gelangen und eine horizontale Bewegung
des Führungsansatzes (40) zum Torvorhang (20) hin zu begrenzen.
5. Trennbare Führungsvorrichtung nach Anspruch 1, bei welcher an dem Bodenelementabschnitt
(45) oder an dem Führungsansatz (40) eine Drehbewegung durchführbar ist.
6. Trennbare Führungsvorrichtung nach Anspruch 3, bei welcher das ebene Einsatzteil und
der Kopplungsmagnet drehbar gelagert sind.
7. Trennbare Führungsvorrichtung nach Anspruch 6, bei welcher die drehbare Lagerung ein
erstes und zweites C-förmiges Glied (150, 160) aufweist, wobei das erste C-förmige
Glied an dem ebenen Einsatzteil befestigt ist und das zweite C-förmige Glied an dem
Kopplungsmagneten befestigt ist, wobei das erste und zweite C-förmige Glied einander
gegenüberliegend angeordnet und durch einen Bolzen (170) drehbar verbunden sind.
8. Trennbare Führungsvorrichtung nach Anspruch 7, bei welcher eine Feder (175) an dem
ersten und zweiten C-förmigen Glied angreift, um an dem zweiten Glied eine Rotationskraft
relativ zu dem ersten Glied anzulegen, und bei welcher eine Trennung der magnetischen
Kopplung ermöglicht, daß der Kopplungsmagnet sich um den Bolzen dreht, um mit dem
Seitenrahmen in Kontakt zu gelangen und die Einsatzhälfte in der selben vertikalen
Position zu halten.
9. Trennbare Führungsvorrichtung nach Anspruch 8, bei welcher der Kopplungsmagnet ein
Band (200) mit hoher Reibung an einem Abschnitt aufweist, welcher den Seitenrahmen
nach der Trennung der magnetischen Kopplung kontaktiert, wobei die Reibung zwischen
dem Band und dem Seitenrahmen die Einsatzhälfte in der vertikalen Position hält.
10. Trennbare Führungsvorrichtung nach Anspruch 2, bei welcher das eisenhaltige Glied
ein Magnet ist.
11. Trennbare Führungsvorrichtung nach Anspruch 2, bei welcher der Kopplungsmagnet ein
Elektromagnet ist.
12. Trennbare Führungsvorrichtung nach Anspruch 1, bei welcher der Bodenelementabschnitt
(45) mit einem anpaßbaren weichen Bodenelement (50) verbunden ist.
13. Trennbare Führungsvorrichtung nach Anspruch 2, bei welcher der Kopplungsmagnet (80)
an dem Führungsansatz (40) drehbar befestigt ist, derart, daß nach einer Trennung
des Kopplungsmagneten von dem Bodenelementabschnitt (45) der Kopplungsmagnet sich
relativ zum dem Führungsansatz (40) drehen und an dem vertikalen Führungselement (30)
angreifen kann, um den Führungsansatz (40) in einer vertikalen Position zu halten.
14. Trennbare Führungsvorrichtung nach Anspruch 13, bei welcher der Führungsansatz (40)
und der Kopplungsmagnet (80) schwenkbar gelagert sind und eine Feder (175) mit der
schwenkbaren Lagerung gekoppelt ist, um den Kopplungsmagneten (80) bei einer Trennung
relativ zu dem Führungselement zu drehen.
15. Verfahren zum lösbaren Verbinden von einem Ende eines Rolltorbodenelements (50) an
der Vorderkante (20a) eines Torvorhanges (20) mit einem Führungsansatz (40), der durch
ein vertikales Führungselement (30), welches an einer Seite des Tores angeordnet ist,
aufgenommen und in vertikaler Ebene geführt wird, wobei das Verfahren die Schritte
umfaßt:
Bereitstellen des Führungsansatzes (40), welcher mit dem vertikalen Führungselement
(30) in einem Führungseingriff steht, um den Torvorhang (20) in einer vertikalen Ebene
zu führen;
gekennzeichnet durch:
magnetisches Koppeln des Führungsansatzes (40) mit einem Bodenelementabschnitt (45),
der mit dem Bodenelement (50) verbunden ist; und
Bereitstellen einer Trennung der magnetischen Kopplung, wenn eine Kraft an dem Torvorhang
(20) oberhalb einer vorgegebenen Größe anliegt.
16. Verfahren nach Anspruch 15, bei welchem der Führungsansatz (40) mit einem zweiten
Kopplungsglied ausgestattet wird, welches drehbar an dem Führungsansatz (40) befestigt
ist, und ein Seitenrahmeneinsatz an einem Seitenrahmen nach einer Trennung der Kopplung
gesperrt wird, um ein Herunterfallen des Seitenrahmeneinsatzes zu verhindern.
17. Verfahren nach Anspruch 16, bei welchem der Schritt des Sperrens des Seitenrahmeneinsatzes
ein Drehen des zweiten Kopplungsgliedes um die Drehlagerung des Führungsansatzes (40)
umfaßt, um zu bewirken, daß das zweite Kopplungsglied mit dem vertikalen Führungselement
(30) in Eingriff gelangt.
18. Verfahren nach Anspruch 17, bei welchem das zweite Kopplungsglied magnetisiert wird,
um das Kopplungsglied mit dem vertikalen Führungselement (30) magnetisch zu verbinden.
19. Verfahren nach Anspruch 17, bei welchem das zweite Kopplungsglied mit einem Reibungsband
ausgestattet wird, um das zweite Kopplungsglied mit dem vertikalen Führungselement
(30) in eine Reibverbindung zu bringen.
1. Ensemble de guide de décrochage pour une porte à rideau métallique, la porte à rideau
métallique comprenant une pièce inférieure (50) sur le bord de guidage (20a) d'un
rideau de porte (20), des pièces de guidage vertical (30) étant disposées de chaque
côté de la porte pour recevoir et guider l'ensemble de guide dans un plan vertical,
l'ensemble de guide de décrochage comprenant :
- une extension de guide (40) pouvant s'engager dans les pièces de guidage vertical
(30) pour guider le rideau de porte (20) dans un plan vertical ;
- une partie de pièce inférieure (45) pouvant être couplée à une extrémité de la pièce
inférieure (50) et s'étendant vers l'extension de guide ;
caractérisé par :
- un couplage magnétique (80, 85) entre l'extension de guide (40) et la partie de
pièce inférieure (45), le couplage magnétique adaptant de façon amovible l'extension
de guide (40) et la partie de pièce inférieure (45) pour des forces appliquées au
rideau de porte (20) en dessous d'une amplitude prédéterminée.
2. Ensemble de guide de décrochage selon la revendication 1, dans lequel le couplage
magnétique comprend un aimant de couplage (80) fixé à l'extension de guide (40) et
une pièce ferreuse (95) fixée à la partie de pièce inférieure (45).
3. Ensemble de guide de décrochage selon la revendication 2, dans lequel l'extension
de guide (40) comprend une pièce plane d'insert (120) reçue à l'intérieur de la pièce
de guidage vertical (30).
4. Ensemble de guide de décrochage selon la revendication 3, dans lequel la pièce plane
d'insert est une plaque de chariot (125), la plaque de chariot recevant des roues
de chariot (130), la pièce de guidage vertical (30) comprenant une projection horizontale
s'étendant à la verticale (35) pour coopérer avec les roues de chariot et pour restreindre
un déplacement horizontal de l'extension de guide (40) en direction du rideau de porte
(20).
5. Ensemble de guide de décrochage selon la revendication 1, dans lequel un déplacement
de pivotement est prévu sur la partie de pièce inférieure (45) ou sur l'extension
de guide (40).
6. Ensemble de guide de décrochage selon la revendication 3, dans lequel la pièce plane
d'insert et l'aimant de couplage sont fixés de façon pivotante.
7. Ensemble de guide de décrochage selon la revendication 6, dans lequel la fixation
pivotante comprend des première et seconde pièces en forme de C (150, 160), la première
pièce en forme de C étant fixée sur la pièce plane d'insert, et la seconde pièce en
forme de C étant fixée à l'aimant de couplage, les première et seconde pièces en forme
de C se faisant face et étant connectées, de façon pivotante, par une broche (170).
8. Ensemble de guide de décrochage selon la revendication 7, dans lequel un ressort (175)
coopère avec les première et seconde pièces en forme de C pour appliquer une force
de rotation à la seconde pièce par rapport à la première, une séparation du couplage
magnétique permettant ainsi à l'aimant de couplage de basculer autour de la broche
pour entrer en contact avec un cadre latéral et pour maintenir la moitié d'insert
dans la même position verticale.
9. Ensemble de guide de décrochage selon la revendication 8, dans lequel l'aimant de
couplage comprend une bande de haut coefficient de frottement (200) sur une partie
en contact avec le cadre latéral après la séparation du couplage magnétique, le frottement
entre la bande et le cadre latéral maintenant la moitié d'insert dans la position
verticale.
10. Ensemble de guide de décrochage selon la revendication 2, dans lequel la pièce ferreuse
est un aimant.
11. Ensemble de guide de décrochage selon la revendication 2, dans lequel l'aimant de
couplage est un électroaimant.
12. Ensemble de guide de décrochage selon la revendication 1, dans lequel la partie de
pièce inférieure (45) est couplée à une pièce inférieure réglable souple (50).
13. Ensemble de guide de décrochage selon la revendication 2, dans lequel l'aimant de
couplage (80) est fixé, de façon pivotante, à l'extension de guidage (40) de telle
façon que, suite à la séparation de l'aimant de couplage de la partie de pièce inférieure
(45), l'aimant de couplage puisse tourner par rapport à l'extension de guidage (40)
et venir en prise avec la pièce de guidage vertical (30) pour maintenir l'extension
de guidage (40) dans une position verticale.
14. Ensemble de guide de décrochage selon la revendication 13, dans lequel l'extension
de guidage (40) et l'aimant de couplage (80) sont fixés, de façon articulée, et un
ressort (175) est couplé à l'articulation pour faire tourner l'aimant de couplage
(80) par rapport à la pièce de guidage lors d'un décrochage.
15. Procédé de connexion amovible d'une extrémité d'une pièce inférieure de porte à rideau
métallique (50) sur le bord de guidage (20a) d'un rideau de porte (20) avec une extension
de guidage (40) reçue et guidée dans un plan vertical par une pièce de guidage s'étendant
à la verticale (30) disposée sur un côté de la porte, procédé comprenant les étapes
suivantes :
- prévoir de l'extension de guide (40) coopérant par guidage avec la pièce de guidage
s'étendant à la verticale (30) pour guider le rideau de porte (20) dans un plan vertical
;
caractérisé par :
- coupler magnétiquement l'extension de guidage (40) sur une partie de pièce inférieure
(45) couplée à la pièce inférieure (50) ; et
- permettre une rupture du couplage magnétique lors de l'application d'une force sur
le rideau de porte (20) au-dessus d'une amplitude prédéterminée.
16. Procédé selon la revendication 15, comprenant le fait de pourvoir l'extension de guide
(40) d'une seconde pièce de couplage fixée, de façon pivotante, sur l'extension de
guide (40) et de bloquer un insert de cadre latéral sur un cadre latéral après la
rupture du couplage afin d'empêcher une chute de l'insert de cadre latéral.
17. Procédé selon la revendication 16, selon lequel l'étape de blocage de l'insert de
cadre latéral comprend une rotation de la seconde pièce de couplage autour de la fixation
pivotante de l'extension de guidage (40) pour provoquer un engagement de la seconde
pièce de couplage avec la pièce de guidage s'étendant à la verticale (30).
18. Procédé selon la revendication 17, comprenant une étape de magnétisation de la seconde
pièce de couplage pour coupler, de façon magnétique, la pièce de couplage avec la
pièce de guidage s'étendant à la verticale (30).
19. Procédé selon la revendication 17, comprenant une étape consistant à pourvoir la seconde
pièce de couplage d'une bande de frottement pour coupler par frottement la seconde
pièce de couplage avec la pièce de guidage s'étendant à la verticale (30).